This research consists of an epidemiolgic study of depression and help-seeking behavior among the adult population of Los Angeles County. The major objectives are to provide estimates of the prevalence and incidence of depression, and to identify causal factors and outcomes associated with this condition. The factors examined include: life event stressors, physical health status, health care utilization, medication use, and social support networks. A sample of 1,000 adults representative of the Los Angeles County population were studied for one year. Four interviews were conducted quarterly, beginning in May, 1979. The interviews were face-to-face for the initial and final waves of data collection, and by telephone for the second and third waves. At the time of the final panel interview (May, 1980) a new control sample of 500 was interviewed to assess the reactiveness of the panel study, and to compare the two interview modes. Due to the large Hispanic community, interviews were conducted in both English and Spanish. The major instrument for classifying depression is the NIMH CES-D scale. In addition to delineating the causes and consequences of depression, this project studies the role of social support systems on the use of community health services by individuals identified as depressed. The relationship between depression and cigarette smoking, alcohol consumption, and the use of medications were also examined.